Integral valorization of Acacia dealbata wood in organic medium catalyzed by an acidic ionic liquid.

In this work, a novel delignification process was proposed for the fractionation of invasive species such as Acacia dealbata wood. Organosolv process catalyzed with an acidic ionic liquid, 1-butyl-3-methylimidazolium hydrosulfate was evaluated to obtain cellulose-enriched solids and liquid fractions rich in hemicelluloses derived compounds and lignin. Under selected operating conditions (190 °C, 60% ethanol, 60 min of reaction time and 0.6 g 1-butyl-3-methylimidazolium hydrosulfate/g wood), high solubilization of lignin and hemicelluloses and cellulose recovery (87.5%, 88.7% and 88.3%, respectively), with a pulp yield of 43.1% were achieved. Moreover, 62.6 % of lignin was recovered by precipitation from the black liquor (composed mainly by 4.43 g xylose/L, 7.66 g furfural/L and 3.59 g acetic acid/L). In addition, enzymatic digestibility of delignified wood was also assayed. Overall, this work presents an alternative biorefinery scheme based in the use of environmentally friendly solvent and catalyst for selective fractionation of A. dealbata wood.

Biorefinery of olive pruning using various processes.

Biorefinery developed involve separation of olive pruning into two parts: main (OPM) (stems>1cm diameter), and residual (OPR) (stems<1cm diameter, and leaves). OPM was submitted to hydrothermal treatment, separating: a liquid fraction (HL), rich in products of hemicelluloses decomposition, and other solid (HS), rich in cellulose and lignin. HS is subject to pulping, resulting: a liquid fraction (HPL), rich in lignin, and other solid (HPS), rich in cellulose. Up to 42% of the polysaccharides from OPM were recovered in HL as valuable compounds. HPS can be used for the bioethanol production by saccharification and fermentation, reaching a bioethanol conversion of 90.6% of the theoretical value. In addition, HPS obtained paper with lower strength properties than those of paper obtained from OPM pulp directly. OPR provided 18.70 MkJ/t heating values, 1094-2234°C flame temperature, and 45-53°C dew point temperature, with a cost of the unit of heat (3.20 €/MkJ) much lower than fossil fuels fluids.